The crash and explosion incinerated a large swath of downtown Lac Megantic, Quebec last July.

Quebec provincial police spokeswoman Aurelie Guindon said Tuesday the investigation was officially completed Saturday and the case is now in the hands of the province's director of criminal and penal prosecutions.

Neither the prosecution nor police would discuss the results of the probe. There is no timetable for potential charges.

Police said last summer their investigation would focus on the possibility of criminal negligence.

The train belonging to the Montreal, Maine & Atlantic Railway rolled into town carrying volatile crude oil from North Dakota's Bakken region.